The most common tuning is D-G-B-D (from lower to higher pitches); other tunings include G-G-B-D and A-A-C#-E. Guitarists often use D-G-B-E tuning to emulate the last four strings of the guitar.
There are different kinds of cavaquinho. The cavaquinho minhoto, associated with the Minho region in Portugal, has the neck on the same level as the body, and the sound hole is usually in the raia format (raia is Portuguese for batoidea).
The Brazilian cavaquinho, associated with Brazil, as the cavaquinhos associated with Lisboa and Madeira, differs from the minhoto in that its neck is elevated in relation to the body, and the sound hole is traditionally round; thus it is more akin to the traditional guitar.
In Spain there is a similar instrument to the Portuguese cavaquinho, belonging to the family of the guitar, called the requinto, which also has four strings, a flat bridge, cover and ten fret wires, whose tune is D-A-C#-E from low to high pitches. Jorge Dias believes it was imported from Spain too, where the guitarra, guitarrón, or guitarrico are also found, along with the Italian chitarrino, saying: "Without setting a date for its introduction, we must acknowledge the remarkable honour that the cavaquinho achieved in Minho thanks to traditional music of a popular character, its joyful songs, its lively dances... The cavaquinho, as a rhythmic and harmonic instrument with its own vibrating and cheerful sound, is one of the fittest instruments for accompanying viras, chulas, males, canas-verdes, verdegares, prins."
It is a very important instrument in Brazilian music, especially for samba and choro. The standard tuning in Brazil is D-G-B-D (although D-G-B-E and the mandolin tuning G-D-A-E are also used for soloing). Some of the most important players and composers of the instrument's Brazilian incarnation are: Waldir Azevedo, Henrique Cazes, Paulinho da Viola, Luciana Rabello, Alceu Maia, Mauro Diniz and Paulinho Soares. The samba cavaco is the connection between the rhythm and harmony sections, playing the rhythm comping. It is played with a pick, with sophisticated percussive strumming beats, unlike the picture above.
The cavaquinho is also found in other places where the Portuguese left an imprint, namely Cape Verde and the USA (especially Hawaii), and became an important part of the popular music of those places.
The Hawaiian Islands have an instrument very similar to the cavaquinho, called the ukulele, which is considered to be based on the cavaquinho, brought to the island by Portuguese immigrants. The Hawaiian ukulele has also four strings and a very similar shape to the cavaquinho, which was introduced into Hawaii by Augusto Dias, Manuel Nunes, and João Fernandes in 1879.
During the 15th Century the four-course cavaquinho was brought to Africa by Portuguese sailors.